High-voltage strain-insulator.



L. STEINBERGER. HIGH VOLTAGE STRAIN INSULATVOR.

APPLICATION FILED APR. l8. 19W.

Patented Nov. 16, 1915.

WITUEWES: Maw? ATTMIEN OFFICE.

LOUIS STEINBERGER, 0F BROOKLYN, NEW YORK.

H IGH-VOLTAGE STRAIN-INSUIATOR.

Specification of Letters Patent.

Patented Nov. 16, 1915.

Application filed Apr-i118, 1910. Serial No. 556,071.

To all whom it may concern Be it known that I, LOUIS STEINBERGER, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved High-Voltage Strain-Insulator, of which the following is a full, clear, and exact description.

My invention relates to insulators, for high voltage electric conductors to. be used in various relations and for various purposes, and more especially to strain insulators for use on transmission lines, and for guy wires or cables employed as stays for towers or for poles, masts, and other supports used in wireless telegraphy and telephony as well as in ordinary commercial work.

I seek among other things to provide an insulator which is compact and simple in construction, low in cost, and capable of withstanding a considerable. mechanical stress and very high voltages; the insulator being as far as practicable proof against the evils of leakage, arcing and puncturing.

Other objects of my invention are the following: to provide tension members with fastening members of such form as to enable a person to attach them or remove them at will: to protect from the weather a portion of the insulating member, terminal, conductor or guy as the case may be, employed in connection with the insulator: to provide an aperture within the insulator adapted to detachably receive a strain member, and to form the insulator into such protective parts as will effectively prevent the entrance of moisture into the aperture, such as will also cover and protect a considerable portion, if not the whole, of'the strain member, which extends outside the apertures, and such as will even cover and protect the attaching eye forming part carried by the strain member, to the end that all'of these parts may not be subjected to the deteriorat ing effects of the elements, and to the end that it may be unnecessary to fill or close the unoccupied space in the aperture with ce- ,ment or like material, the presence of which would prevent the ready detachability of the strain member; to prevent the line wire or guy wire from falling in the event that the msulating member or any part thereof becomes in ured or destroyed: to give the various parts such form as will tend to prevent leakage, arcing or puncturing, under the influence of currents of high potential and to adapt the device for application in various relations: to dispose the strain members in such relation to each other that the insulating member located between them will be subjected to a crushing action only, whenever the insulator is in actual service: and to provide an insulator possessing the highest possible form of electrical insulation combined with great mechanical strength My invention further seeks to render the insulator unit flexible in relation to its supports, and if more than one such unit is employed, to render such units flexible to each other.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in both figures.

Figure 1 is a view partly in section and partly in elevation, showing a pair of my improved insulators connected together and disposed vertically for purposes of supporting a line or for guying or the like; Fig. 2 is a view partly in section and partly in elevation, showing two of the insulators connected head to head and disposed horizontally for purposes of a strain insulator, for dead ending or the like.

When considering two juxtaposed conductors as being insulated from each other, it is apparent that any protection afforded one of the conductors, serves equally well for both. That is to say, that supplying a given, sufiicient, amount of insulating material and protection to one of the conductors will prevent a. flow.of current between the conductors the same as if that amount of insulating material and protection were distributed to the two conductors. One of the conductors may therefore be wholly exposed, if desired, so long as the other is amply protectcd. I have made use of these facts in devising the structure disclosed in the accompanying drawings in such wise that one of the conductors, or strain members, which I employ, being .more'or less exposed and accessible, is rendered very easily detachable for exchange with others of varying lengths and capacities, or for removal in case of breakage, etc., while the other conductor, or strain member, is protected to a very high degree, not only from physical contact with the first, but also particularly against attacks of moisture and dust, with their attendant evils. The second strain member, in the structure which I have devised, is also easily detachable and readily interchangeable with others of varying lengths and capacities, though, in this instance the exchange may be subject to slightly more inconvenience thanwith the first, or exposed,

I conductor, owing to its relatively sealed disposition. The invention thus provides a structure comprising an arrangement of strain members thoroughly insulated from each other, and having the other characteristics above pointed out, which may be very easily altered to meet minor variations 1n existing requirements, such as are encountered in the great majority of instances;

and which may be further altered in other or unusual instances. In order to accomplish these desirable and practical results I have provided a preferably substantially cylindrical body of insulating material designated as 3 on the drawings. This body is hollowed out for the greater portion of its length to form a deep, frusto-conically shaped, protective chamber 4 for the strain member 8, which shall hereinafter be referred to as the protected strain member. The remainder of the body 3 is relatively solid as at 6, though of somewhat smaller diameter than the hollowed portion 3, and the end of the solid portion is preferably rounded into hemispherical shape. Extending transversely through the relatively solid portion 6 is a straight aperture or passage 14. A U-shaped passage? is formed through the portion 6 having its rounded or looped portion 7 arranged substantially concentric with the outervhemispherically shaped surface of the portion 6, and having its two legs formed straight and arranged in strictly parallel relation and opening into the cup shaped orhollow portion 4 of the body, said straight legs being substantially parallel with thelongitudinal axis of the body 3. The legs 7 are spaced equi-distance upon opposite sides of the transverse aperture 14 so as to dispose a considerable quantity, or bulk, of the insulating material, of which the body is formed, intermediate said legs and the aperture 14. The rounded or looped portion 7 is substantially concentric with the center of the transverse aperture 14 though it is preferably arranged so that its inner surface is spaced a slightly greater distance from the transverse aperture 14 than is the inner sur-' face of the legs 7, so as to dispose a greater bulk of insulating material between itself and the transverse aperture 14 in the line of strain. a

verse aperture or passage 14, having its opposite ends bent toward each other about the hemispherical end of the part 6 and connected by a clamp 10 similar to that connecting the ends of the protected strain member. This strain member 15 is preferably also of a flexible material and, upon detachment of the clamp from its ends, it may be immediately detached from the straight, comparatively exposed, aperture 14 and be exchanged for one of greater strength, varying length, cm, as conditions may require.

At the point where the relatively solid portion 6 of the body 3 merges into the hollowed portion thereof, the body is formed with an annular flange or hood 5 which projects outwardly for a suilicient distance to protect the exterior surface of the hollowed portion of the body 3 from direct attack of rain water, etc., and to assist the walls of the hollowed portion in protecting the protected conductor and attached metallic parts. Assuming the insulator to be arranged in vertical relation, as shown in Fig. l, the flange or hood 5' may be described as having its upper surface inclining outwardly and downwardly, and its under surface likewise inclined outwardly and downwardly away from the body 3 so as to preclude the possibility of a flow of moisture toward said body. The hollowed, frusto-conically shaped, portion 4 is arranged with its smallest diameter lnnermost so as to prevent a flow of moisture toward the inner end thereof, and into the legs of the U-shaped aperture 7, even when the insulator is arranged in a horizontal position as shown in Fig. 2. This hollowed portion being of a comparatively great length and practically inclosing the otherwise exposed portions of the protected conductor 8 from the point where it merges from the U-shaped aperture 7, forms an eflicient means of excluding .moisture and dust from the interstices left within the aperture by the relatively loose fit of the member 8 therein, and obviates the necessity for filling these interstices with cement, the presence of which would prevent a ready detachment and subsequentfreadjustment of the strain member 8.

The exclusion of moisture from the pasthrough which it might flow and form a conducting path to the other strain member and would ultimately fracture and destroy the insulator. These disasters are overcome by the extensive protection afforded by the rela-' tively deep, open, hollow portion 4, within which dry air may freely circulate, and the protected conductor, at the same time, is maintained readily. detachable.

The clamps 10 described for connecting the loose' ends of the strain or conductor members 8 and 15 are two-part clamps, having generally the form of a Y, and are provided with eyes 11. These clamps are mounted upon the ends of the strain members in such manner as to conceal the joint which is preferably made by twisting the ends of the strain members together, as at 9. The eyes 11 are in pairs, and extending through each pair is a bolt 12 which holds the two parts of the respectiveclamp together. Each clamp provides a pocket 13, comprising the stem of the Y, while the opposite legs of the Y project outwardly therefrom, the clamp 10 holding the ends of the protected conductor 8, having its two legs arranged so as to space the exposed portions of the protected conductor apart a distance corresponding to the space between the legs of the U-shaped aperture 7 in the insulator body, while the strain member 15, upon leaving the legs along the sides of the portion 6 of the insulator body, said portion being of somewhat greater width than the clamp. This arrangement produces, in practice, a force tending to crush the sides of the portion 6 toward each other, which tendency serves to assist the material of the insulator in resisting the direct pull of the strain member and prevents chipping or fracture of the material of the insulator, which might result from a straight pull from the ends of the passage 14. A compression strain is set up from the material at the end portions of the openings 14, substantially in a direction toward the strain member 8, rather than a shearing strain past said member 8, as would appear if the legs of the strain member 15 were arranged parallel, or were inclined in an opposite direction to that illustrated. Each of the clamps provides a pocket, in the hollow of the Y, adapted to 'be directly engaged for supporting another insulator, or

for engaging a support for the present insulator, as the case may be.

It is apparent that upon detachment of of its clamp 10 flares outwardly the clamp 10 from the ends of the protected strain member 8, said strain member may be detached and have substituted therefor a strain member of a different capacity or a different length, as desired. If. a shorter member 8 is used, then the clamp 10 may be I disposed wholly within the hollowed portion 4 and will thus be more ed, which arrangement desirable in unusual instances.

Insulators of the class disclosed herein are particularly designed for use as one of a series of interlinked insulator units, such as effectually protectmay be necessary or form what is known as a chain type insulator.

It is seen that I have done away with the use of separately formed connecting members for the units of my chain-type insulator. Each unit, with its two strain members is complete in itself. Each strain member comprises a closed link and a separately formed part, which may be readily disconnected to open the link and which may be as readily again attached to close and lock the link and which will form a reinforced open seat within which the next unit may loosely rest.

The complete insulator unit comprises the body of insulating material, a strain member 8 and a strain member 15, together with a clamp 10 upon each of these strain members. Each insulator body with its accompanying parts, I consider as a unit. Any number of units may be chained up together, as indicated in Fig. 1, and used to support a line or employed in any other relation wherein it is desirable to virtually add together the various insulative powers of several units. If desired, two units may be placed head to head, as indicated in Fig. 2, this arrangement being referable where the device is used for purposes of a double unit strain in sulator. If desired, however, multiple units may be used for purposes of a strain insulator, as Well as for other purposes.

Owing to the novel construction of my strain insulator, it ,will be observed that for any given size of insulator body it provides the greatest possible insulating area for the prevention of surface leakage and also the tendency to are and to puncture, thereby providing a very large factor of safety.

The disposition of the tension members relatively to each other and to the insulating member is such that the insulator is entirely exempt from all but compression strains and hence possesses exceptionallv great mechanical strength combined with the highest possible form of electrical insulation. These insulators may be used separately or any num ber of them may be linked or connected together, or connected to insulators ofdiflerent form, in any preferred manner, so as to increase the aggregate insulation for supto any particular combination of the parts;

neither do I limit myself to the use of any prescribed materials, as in some instances I may employ a tough insulating material such as electrose or I may employ a brittle in-' sulating material suchas porcelain or other brittle material, the flexibility of the links and the location of the passages 7 and 14 are such that the various mechanical strains are distributed to the best advantage, so as to preserve the insulator body and also to protect the tension members.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In a device of the class described, the combination comprising an elongated body portion of insulating material hollowed out for the greater portion of its length to form an elongated chamber longitudinally of the body having an end wall deep within the body of only slightly less diameter than the open end of the chamber, and the side walls of the chamber being substantially straight and converging little, and said body having a U-shaped aperture formed in the remainder of its length arranged with two straight, substantially parallel disposed legs extendinglongitudinally of the body, and opening through the end wall of said chamber, opposed strain members, one of which is disposed loosely insaid U-shaped aperture, readily detachable therefrom, having exposed end portions extending into said chamber, and being formed with means for attaching a supported conductor, the other strain member extending through an aperture formed in a straight line transversely entirely through the body and through the loop defined by the U-shaped aperture, the

deep chamber within the body serving to effectually protect the U-sha'ped aperture from moisture, whereby to avoid the necessity for filling the interstices with cementor other material to exclude moisture.

2. In a chain-type insulator, the combination comprising a body of insulating material, having a U-shaped aperture formed therein arranged with its two legs opening out toward one end of said body, and having a second aperture formed in a straight line transversely entirely through said body at an angle to the plane of the first aperture, and through the loop defined by the first aperture, a U-shaped strain member disposed said U-shaped aperture, a second strain member formed of flexible material threaded through the straight transverse a erture and rojecting from opposite ends 0 said straig t aperture so as to be easily detachable, said second strain member be ing bent at the opposite ends of the straight transverse aperture into relatively inclined portions convergin toward each other beyond the body, an impinging against the opposite sidesurfaces of the body adjacent t e ends'of said straight transverse aperture, and means connecting together the ends of said second strain member, adapted to hold the ends in converged relation and to form an open seat for a supported conductor, the inclined relation of the end porgether and for providing an open seat between said strain members within which a support may loosely rest.

4. In an insulator, a body portion of insulating material, a plurality of flexible strain members extending therefrom in spaced relation having their ends twisted together, and a detachable clamp member having a part engaging over said twisted ends to prevent their becoming untwisted and also having a U-shaped part to provide an open seat between the strain member -within which a support may loosely rest.

5. In a chain-type insulator, a pair of insulator units spaced apart, a separately formed strain member carried by each unit extending toward the other unit, each comprising a closed' link of flexible material,

and at least one of said closed links comprising a separately formed part of nonflexible material readily detachable for opening that link, and said separatelyformed part, when attached to close the link, being adapted to form an open seat upon that link within which the other link may loosely engage. 4

6. In an insulator, a body portion of insulating material, a pair of flexible strain members extending therefrom in spaced relation having their ends twisted together, and a detachable Y-shaped clamp member, the stem part of the Y being in clamped engagement with the twisted end portions of the strain members to retain said portions twisted and the opposite legs of the Y extending along and being in clamped enbers for connecting said strain members togagement with the two strain members re- In testimony whereof I have signed my spectively to further retain them a ainst name to this specification in the presence of disconnection from each other and a so to .two subscribing witnesses.

provide an open seat between the legs of LOUIS 'STEINBERGER. 5 the Y within which a support may loosely Witnesses:

rest, and means for attaching a. conductor WAL'IUNIHAVRRIBION, to said insulator. PHIIJP D; Rommus. 

